Humans have long known how important fungus is. The antibiotic penicillin, derived from the fungi Penicillium, battles bacterial infections. Other fungi are used as food-fermenting agents: Saccharomyces cerevisiae is used to make beer and wine and Aspergillus oryzae is used to make miso and soy sauce. Fermentation enhances food's nutritional values, improves flavour and increases shelf life.
But what about mould? Do you think it can be helpful to humans? To students from City University of Hong Kong, the answer is "yes".
Students are researching a kind of mould-like microbe called slime mould, aka Physarum polycephalum. This yellow, gluey slime mould usually appears in the form of plasmodia, which looks like scrambled eggs. It grows by itself into a network, with some blobs at certain spots as it extends outward. It moves relatively quickly compared to other microbes: the mould can "crawl" at 1cm per hour.
Slime mould crawls in a highly efficient way when it forages for food. For example, if slime mould wanted to reach Tiu Keng Leng from Central, it would opt for the Island Line instead of taking the Tsuen Wan and Kwun Tong lines.
Using a specially designed maze, researchers from Japan's Hokkaido University successfully proved that slime mould will find the shortest path to reach food, avoiding three longer paths.
They also made a miniature version of the Tokyo metro system with the help of slime mould, marking Tokyo's landmarks with slime mould's favourite food: the oats we eat.
The researchers used light, which slime mould doesn't like, to simulate prohibitive terrain, like lakes and mountains.
Eventually, the mould foraged in a network that was very similar to the real Tokyo subway.
The CityU students want to discover what is actually going on in the mind of slime mould.
Under the guidance of their professors, the students are investigating the behaviour of slime mould when faced with different environmental stimuli, for example, food it likes (oat flakes) and things it dislikes (light).